Fuel injectors are devices used on internal combustion engines for the delivery of fuel into the cylinder of the engine. The fuel injectors are mechanically driven from the camshaft of the engine, via a rocker arm mechanism, a cam and a cam follower. The mechanical mechanism actuates a plunger which reciprocates within a bore of the fuel injector and in turn actuates a piston also located within the bore. Located between the plunger and the piston is a timing chamber and located between the piston and the nozzle of the fuel injector is a metering chamber. By supplying pressurized fluid to the timing and metering chambers and by controlling the amount of fluid into and out of these chambers by one or more valves, one can control both the timing and the metering of fuel into the combustion chamber of the engine. During the operation of such fuel injectors, there is a buildup of pressure within the timing chamber during a portion of the cycle and this pressure could become very high. One of the present problems with such fuel injectors is a need to prevent leakage around the valve which controls the passage of fuel into and out of the timing chamber. Various attempts have been made to alleviate this problem but few have been fully satisfactory due to the large pressure values. One solution uses a sliding valve and is taught in U.S. Pat. Nos. 4,235,374 and 4,281,792. However, the use of such a slide valve does not substantially solve the leakage problem. In addition to providing a low pressure seal to prevent leakage of fuel from the timing chamber during high pressure situations, there is also a need to create a seal which exerts a minimum amount of drag force on the valve as it rapidly reciprocates between an open and a closed position. Now a sealing arrangement has been invented which will satisfy these needs.